8 Replies Latest reply on Jul 3, 2019 6:49 AM by e14softwareuk

    Back Annotation Broken

    r.gibson

      I am trying to re-annotate the PCB and then push the re-annotated reference designators back to the schematic. Unfortunately, every time I try, Altium breaks all sorts of links and then asks me to try to match the unmatched nets without offering any ability to cross probe or zoom to the net location either on the schematic or on the PCB...horribly frustrating. I've had to manually revert to an older saved file several times now because it's so messed up. Has anyone else had luck with this? Maybe I'm just doing something wrong, but I don't think so...this should be a really easy process and it's NOT!

        • Re: Back Annotation Broken

          Hi Ryan, sorry to hear of the frustrations with back annotation. Before starting to rename components on the PCB did the designs match? Things to check are that the component instances align between PCB and schematic (PCB editor: Tools | Component Links) and the netlists match (Schematic editor: Home | Projects > Update PCB Document). Also be aware that back annotation does not work if using repeated design blocks. If you cannot get back annotation working then feel free to reach out to me (a private message or email software@element14.com) and if you can supply a copy of your design I will take a look.

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            • Re: Back Annotation Broken
              r.gibson

              I verified that the links and netlists match...that was the first thing I tried. I'm not using any repeated design blocks.

              I just sent my project package to your Farnell account...hopefully you can figure out why it's not working...

                • Re: Back Annotation Broken
                  voltsandjolts

                  Maybe you are doing this already but....

                   

                  After doing the back-annotate operation the schematic symbols should have two designators, with the greyed out one being the old designator.

                  It is important to recompile the project at that point before doing anything else.

                   

                  After the recompile your schematic net names will change (since auto net names are based upon component designators), so you must pull those net name changes into the PCB (Project > Import Changes)

                  2 of 2 people found this helpful
                    • Re: Back Annotation Broken
                      r.gibson

                      That is a lot of steps for something that should be much simpler...however what you say does make sense. I will try your suggestions this evening and see if that is the problem. If that is the case, it would be nice if Altium could be a little smarter and handle the net renaming automatically...since one of the main advantages that Altium has over it's competitors is the integration between Schematic and PCB software tools.

                  • Re: Back Annotation Broken
                    g_catlin

                    Very helpful.

                    I got the PCB re-annotation done, pushed it to the schematics, I think I recompiled, then updated the PCB.  I had to manually correct one net name because of a wrong reference number, and 5 or 6 connector pins that had   _1  added. The pad needed to be edited (delete "_1" ) to allow the ECO to resync the PCB to SCH. Everything seems to be correct from schematics to PCB but the Variants are totally messed up due to pointing to the wrong refdes. 

                     

                    Is there a part of this sequence that requires a certain order of save operation or a way ensure that the was-is file is used for Variants?

                     

                    FYI to all who re_annotate, as noted elsewhere: Is there a reference designator feature in CircuitStudio to automate or re-annotate from PCB?

                    "After doing this re-annotation check that your silk/overlay component designators still fit.  It is easy to have C1 change to C112 and no longer fit next to a pad or via."